----- Original Message -----
From: "Paul Christensen" <w9ac@arrl.net>
> > A possible solution to the problem of bandwidth vs. quality is to
> > develop of form of digital audio encoding that employs a data
> > compression scheme similar to the variable bit rate method that's
used
> > in some forms of mp3 encoding.
>
> A good point, Vic -- and to the League's point in their proposal, I
believe
> the intent is to foster emerging digital technologies to do just
what you
> describe. In fact, not only is the technology here, but the product
is too.
> See the following link:
>
> http://www.aorusa.com/ard9800.html
>
> With a bit of data augmentation, such a product has real promise for
those
> wanting to explore high fidelity audio on the HF bands. The
modulation
> technique in this unit is DPQSK.
>
> Since this is an AMPS mail group after all, I am interested in
knowing more
> about the peak-to-average ratio of the data and how it fits within
the
> acceptable duty-cycle of today's commercially-manufactured
amplifiers.
this is a wrong way to go, this modem wants a lot of bandwith:
"Be sure your audio filters are about 3KHz or wider."
This will not be allowed in Germany as bandwith is restricted to
2,7KHz on all bands
below 28 MHz.
It is using normal SSB circuits and makes no use of high efficient
modulation techniques
73
Peter
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